What are rootkits and how to detect them in the operating system?

Rootkits represent one of the most dangerous types of malware, the purpose of which is to hide the presence of other threats in the system. They integrate deeply into the operating system by intercepting its system calls and spoofing the results of standard utilities. This causes infected files, processes, and network connections to become invisible to ordinary antivirus scanners.

Specialized utilities are used to detect rootkits, capable of analyzing system operation bypassing standard API interfaces. Such programs check the integrity of system interrupt tables and compare the real memory contents with what the operating system returns. Sometimes, to check the disk, you have to boot from an external media to neutralize an active rootkit.

If a rootkit is deeply embedded in the system kernel or UEFI, standard removal becomes impossible or does not guarantee security. In such cases, the only reliable solution is a complete format of the hard drive and reinstallation of the operating system followed by data restoration from clean backups.